1. Field of the Invention
The present invention relates to surgical sutures and their production. More particularly, the invention relates to an apparatus and method for attaching surgical needles to surgical sutures.
2. Description of the Related Art
The trend to develop and produce surgical sutures attached to eyeless surgical needles is continuously evolving. The most common surgical suture of this type is a single-use needle of appropriate size and shape which is attached to the end of the suture, so that the needle is used once and then discarded.
The attachment can be accomplished by use of a "drilled end" needle, that is, one in which a concentric aperture is formed in the end face of the needle, in which the suture is placed in the aperture and the needle is crimped around the suture. Alternatively, a "flanged" needle may be utilized in which a U-shaped channel is stamped into the end of the needle with the ends of the "U" being crimped about the suture to hold the suture together. The attachment must be one which is predictably secure, causes a minimum of damage to tissue, is convenient for the using surgeon, permits sterilization and entails reasonable costs. In addition, the attachment must withstand the rigors of manufacture, sterilization, storage, shipment and use.
With conventional crimping operations a crimp is created between several dies which close to a fixed gap. Any variation in the crimping dies, the needle size, the hole size, or the suture size alters the degree of crimp.
Conventional crimping methods require the back end of the needle be struck with two half moon shaped dies. The needle is then manually rotated 90.degree. and the needle is struck again with the dies. The manual intervention in the production of surgical sutures with eyeless needles reduces production efficiency and increases the associated costs incurred in their manufacture.
To date, techniques devised for connecting such suture components in a manner to perform within the preferred guidelines are not as effective for high speed production of surgical sutures as would otherwise be desirable. The present invention avoids the aforementioned disadvantages and provides a needle crimping apparatus which automatically rotates the dies 90.degree. so as to reduce the need for manual rotation of the needle as described above.